Adsorption of CO2 from dry gases on MCM-41 silica at ambient temperature and high pressure. 2: Adsorption of CO2/N2, CO2/CH4 and CO2/H2 binary mixtures

Adsorption equilibrium capacity of CO2, CH4, N2, H2 and O2 on periodic mesoporous MCM-41 silica was measured gravimetrically at room temperature and pressure up to 25 bar. The ideal adsorption solution theory (IAST) was validated and used for the prediction of CO2/N2, CO2/CH4, CO2/H2 binary mixture adsorption equilibria on MCM-41 using single components adsorption data. In all cases, MCM-41 showed preferential CO2 adsorption in comparison to the other gases, in agreement with CO2/N2, CO2/CH4, CO2/H2 selectivity determined using IAST. In comparison to well known benchmark CO2 adsorbents like activated carbons, zeolites and metal-organic frameworks (MOFs), MCM-41 showed good CO2 separation performances from CO2/N2, CO2/CH4 and CO2/H2 binary mixtures at high pressure, via pressure swing adsorption by utilizing a medium pressure desorption process (PSA-H/M). The working CO2 capacity of MCM-41 in the aforementioned binary mixtures using PSA-H/M is generally higher than 13X zeolite and comparable to different activated carbons.